Influenced by the Arts and Crafts movement and the ideals of the old New England farm, Riddle designed and supervised the building of the school over a span of 10 years, from 1918 to 1927, which cost her over $7,000,000 to complete.

The original stone and oak architecture is modeled after English Cotswold and Tudor styles using traditional English methods with many of the materials hewn from the school's property. The school sits upon 900 acres, with the Farmington River to the east.